Outline of the Byzantine Empire

The following outline is provided as an overview of and topical guide to the Byzantine Empire:

Byzantine Empire (or Byzantium) – the Constantinople-centred Roman Empire of the Middle Ages. It is also referred to as the Eastern Roman Empire, primarily in the context of Late Antiquity, while the Roman Empire was still administered with separate eastern and western political centres. In its own time, there was no such thing as "the Byzantine Empire," there was just the on-going Roman Empire; "Byzantine Empire" is a scholarly term of convenience to differentiate the empire from its earlier existence during classical antiquity before the western half collapsed (see decline of the Roman Empire). Its citizens continued to refer to their empire as the Roman Empire (Greek: Βασιλεία Ῥωμαίων, Basileia Rhōmaiōn;[1]Latin: Imperium Romanum) or Romania (Ῥωμανία).[2] After the Western Roman Empire fragmented and collapsed in the 5th century, the eastern half continued to thrive, existing for an additional thousand years until it fell to the Ottoman Turks in 1453. During much of its existence, the empire was the most powerful economic, cultural, and military force in Europe.

The Eastern Roman Empire (purple) and its vassals (pink) in 555 AD during the reign of Justinian I. The vassals are the Kingdom of Lazica and the Abasgians (top), and the Ghassanids (east). This was the Byzantine Empire at its greatest extent.